Recently, Pérez-Bibbins et al. (2014) observed that the use of the
solid fraction of wine, cider and beer lees did not allow the development
of D. hansenii cultures. In consequence, two methods of cell
disruption were assessed: one mechanical using a high-pressure
homogenizer, and one non-mechanical, consisting in the autolysis
of cells. Only autolysis of beer lees proved to be successful (see
Table 3) for producing xylitol using whole lees or the solid fraction.
Therefore, using the solid fraction of beer lees after autolysis,
the fermentative parameters (P = 34.8 g/L, QP = 0.363 g/L h and
YP/S = 0.67 g/g) were close to those achieved using synthetic media
(P = 39.3 g/L, QP = 0.409 g/L h and YP/S = 0.80 g/g) or yeast extract as
the only nutrient (P = 40.2 g/L, QP = 0.559 g/L h and YP/S = 0.80 g/g),
meaning that the solid fraction of beer lees could be employed as
economic nutrient after an autolysis treatment. These authors
conclude that these results could be attributed to the amount of
available nitrogen after the treatment.